Every year, millions of people come to take in the park’s scenic rockbound coastline. But some of those visitors are taking parts of that coastline with them, a practice that continues to increase, harms the park and is a federal offense.

“This is something that has always been occurring, but seems in the last few years it has gotten worse,” Richard Rechholtz, supervisory park ranger at Acadia, said Sunday morning. “Certain places within the park seem to be targets because those stones on those beaches have round rocks that look so inviting.”

As tempting as it may be to collect a pretty rock or group of pebbles, Rechholtz said it is still illegal, and removing resources from a national park is a federal crime that can result in a fine.

“We rangers are here to protect those resources,” Rechholtz said. “We are here to protect them along with protecting people, helping people who get hurt and helping people enjoy their vacations.”

According to the park’s website, more than 2 million people visit Acadia every year, and as Rechholtz pointed out, if everyone of those 2 million took a pebble, stone or rock, there would be very little park left to enjoy.

“The rocks are here for everyone to enjoy today, tomorrow and the next generation,” he said. “If everyone took one, there would not be any left.”

Rechholtz said taking rocks from Acadia’s beaches is like cutting a tree down in the park’s forests.

Tony Palumbo of western New Jersey, who has been coming to Acadia since he and his wife first visited 26 years ago on their honeymoon, said he has seen his share of rock pickers.

“I’ve seen a lot of it,” Palumbo said Sunday by cellphone as he was on his way to Acadia National Park. “There are certain beaches in particular where people go down to see the stones and end up picking up and taking away handfuls of them.”

“I have asked people if they have not seen the signs that say not to take rocks,” he said. “But some people just don’t care [and] walk right past me like they don’t even see me.”

Palumbo understands how people can think taking just one rock or pebble has no impact on a park the size of Acadia, but he said they have to think of the cumulative effect.

“It’s like anything else when done in excess,” he said. “I may only be one person, but we all know that one person is replicated 20, 30 or 50 people a day, and that is not a small problem when you look at it over a year or a number of years.”

Jenna Beaulieu lives in Bar Harbor surrounded by Acadia National Park and spends a great deal of time exploring and photographing the area. She said Sunday that she understands the inclination to take a piece of it home.

“It is very tempting to take a rock while hiking in the park,” she said. “I know, because I had to fight it this morning while taking photos near Otter Cliffs.”

While not wanting to contribute to “the problem of stripping Maine’s rocky coast,” Beaulieu did say as a native of the state that she does feel a bit “territorial” and would like to take just one stone.

“But at the same time, it’s empowering to know that, by leaving the rock behind, I am doing something nice for this beautiful place,” she said.

Leaving rocks also is becoming an issue, according to Rechholtz, as more and more visitors are constructing rock cairns or other man-made piles along the park’s trails or on some island beaches.

“This is what we call ‘rock art,’” he said. “People building these cairns is really kind of like graffiti, [and] if you go to a pristine park, you start seeing all these piles that people built. … We are asking people to please not stack rocks.”

It’s a particular problem in places such as the park’s Bar Island, Rechholtz said.

“You can’t go out there and not see them,” he said. “People put them up as fast as we knock them down.”

Rechholtz said he understands people love the park so much and want to take a bit of it to remember, some more than others.

“I once saw someone from New York [who] had a station wagon with so many rocks in it, the tires were almost flat,” he said. “He was never going to make it back to New York like that. I don’t know what people are thinking.”